Pharmacokinetics of orally administered single-dose ponazuril in cats.

Cats and kittens in animal shelters and catteries regularly suffer from severe gastrointestinal coccidiosis, which can be fatal, and there are no drugs labeled for feline coccidiosis in the United States. Ponazuril, a triazine-class drug, is increasingly used at a dose of 50 mg/kg/d, orally, for three to five days in shelter environments for coccidiosis. A single oral dose of ponazuril paste 15% (Marquis ; Merial) at 50 mg/kg was administered to six healthy adult cats. Sample analysis was completed via high-performance liquid chromatography. Plasma concentrations peaked at 7.49 ± 2.06 µg/ml at 14.67 ± 7.45 hr post-administration. This study shows that ponazuril achieved a plasma concentration that inhibits growth of similar organisms after a single oral dose in cats. Further studies are necessary to optimize dosing for the treatment of clinical coccidiosis in cats.